A light scanning unit of an image forming apparatus to scan a light beam in forward and reverse directions, the light scanning unit including: a beam deflector to deflect the light beam, and to form forward direction and reverse direction scanning lines in an image section and first and second non-image sections respectively provided on opposite sides of the image section; a reflecting member to reflect a light beam inputted from the beam deflector; and a light detecting unit to receive a first light beam directly inputted from the beam deflector, and a second light beam inputted via the reflecting member, wherein the reflecting member includes a reflecting unit to reflect the inputted light beam to the light detecting unit, and a distinguishing unit to distinguish the reflected second light beam from the first light beam.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A light scanning unit to scan a light beam in forward and reverse directions, the light scanning unit comprising: a light source to emit a light beam; a beam deflector to deflect the light beam, and to form forward direction and reverse direction scanning lines in an image section and first and second non-image sections respectively provided on opposite sides of the image section; a reflecting member to reflect a light beam inputted from the beam deflector; and a light detecting unit to receive a first light beam directly inputted from the beam deflector, and a second light beam inputted via the reflecting member, wherein the reflecting member comprises a reflecting unit to reflect the inputted light beam to the light detecting unit as the second light beam, and a distinguishing unit to distinguish the reflected second light beam from the first light beam.
2. The light scanning unit as claimed in claim 1 , wherein the light detecting unit is provided in the first non-image section and the reflecting member is provided in the second non-image section.
3. The light scanning unit as claimed in claim 1 , wherein: the reflecting unit comprises first and second reflecting areas that are distanced from each other; and the distinguishing unit is provided between the first and second reflecting areas.
4. The light scanning unit as claimed in claim 3 , wherein the distinguishing unit transmits, absorbs, diffuses, and/or diffusedly reflects the light beam that is inputted from the beam deflector, or reflects the inputted light beam away from the light detecting unit.
5. The light scanning unit as claimed in claim 1 , wherein: a time margin between a front end synchronizing signal detecting time of the forward direction scanning line and a starting time of the image section that is adjacent to the second non-image section, determined based on the first and the second light beams received by the light detecting unit, is a first time margin; a time margin between a front end synchronizing signal detecting time of the reverse direction scanning line and a starting time of the image section that is adjacent to the first non-image section, determined based on the first and the second light beams received by the light detecting unit, is a second time margin; and the first time margin and the second time margin are substantially equal.
6. The light scanning unit as claimed in claim 5 , wherein the reflecting member and the light detecting unit are symmetrically provided in the first and the second non-image sections, respectively, with respect to a center of the image section.
7. The light scanning unit as claimed in claim 1 , further comprising a control unit to determine whether the scanning line of the light beam is the forward direction or the reverse direction according to a difference between signals that respectively correspond to the first and the second light beams received by the light detecting unit, and to control the light source to emit a light beam that has the image information corresponding to a scanning direction of the scanning line.
8. The light scanning unit as claimed in claim 1 , wherein the beam deflector comprises a resonance mirror.
9. The light scanning unit as claimed in claim 1 , wherein the light scanning unit comprises only one light detecting unit.
10. A light scanning unit to scan a light beam in forward and reverse directions, the light scanning unit comprising: a light source to emit a light beam; a beam deflector to deflect the light beam, and to form forward direction and reverse direction scanning lines in an image section and first and second non-image sections respectively provided on opposite sides of the image section; a reflecting member comprising at least two reflecting units distanced from each other in order to reflect a light beam inputted from the beam deflector; and a light detecting unit which to receive a first light beam directly inputted from the beam deflector, and a second light beam inputted via the reflecting member.
11. The light scanning unit as claimed in claim 10 , wherein the light detecting unit is provided in the first non-image section and the reflecting member is provided in the second non-image section.
12. The light scanning unit as claimed in claim 10 , wherein: a time margin between a front end synchronizing signal detecting time of the forward direction scanning line and a starting time of the image section that is adjacent to the second non-image section, determined based on the first and the second light beams received by the light detecting unit, is a first time margin; a time margin between a front end synchronizing signal detecting time of the reverse direction scanning line and a starting time of the image section that is adjacent to the first non-image section, determined based on the first and the second light beams received by the light detecting unit, is a second time margin; and the first time margin and the second time margin are substantially equal.
13. The light scanning unit as claimed in claim 12 , wherein the reflecting member and the light detecting unit are symmetrically provided in the first and the second non-image sections, respectively, with respect to a center of the image section.
14. The light scanning unit as claimed in claim 10 , further comprising a control unit to determine whether the scanning line of the light beam is the forward direction or the reverse direction according to a difference between signals that respectively correspond to the first and the second light beams received by the light detecting unit, and to control the light source to emit a light beam that has the image information corresponding to a scanning direction of the scanning line.
15. The light scanning unit as claimed in claim 10 , wherein the beam deflector comprises a resonance mirror.
16. The light scanning unit as claimed in claim 10 , wherein the light scanning unit comprises only one light detecting unit.
17. An image forming apparatus, comprising: an image carrying body; a light scanning unit to scan a light beam on the image carrying body to form a latent image thereon; a developing unit to develop a visible image on the image carrying body according to the latent image; a transferring unit to transfer the visible image developed on the image carrying body to a print medium; and a fusing unit to fuse the visible image transferred to the print medium, wherein the light scanning unit comprises: a light source to emit a light beam, a beam deflector to deflect the light beam, and to form forward direction and reverse direction scanning lines in an image section and first and the second non-image sections respectively provided on opposite sides of the image section, a reflecting member to reflect a light beam inputted from the beam deflector, and a light detecting unit to receive a first light beam directly inputted from the beam deflector, and a second light beam inputted via the reflecting member, wherein the reflecting member comprises a reflecting unit to reflect the inputted light beam to the light detecting unit as the second light beam, and a distinguishing unit to distinguish the reflected second light beam from the first light beam.
18. The image forming apparatus as claimed in claim 17 , wherein the light detecting unit is provided in the first non-image section and the reflecting member is provided in the second non-image section.
19. The image forming apparatus as claimed in claim 17 , wherein: the reflecting unit comprises first and second reflecting areas that are distanced from each other; and the distinguishing unit is provided between the first and the second reflecting areas.
20. The image forming apparatus as claimed in claim 19 , wherein the distinguishing unit transmits, absorbs, diffuses, and/or diffusedly reflects the light beam that is inputted from the beam deflector, or reflects the inputted light beam away from the light detecting unit.
21. The image forming apparatus as claimed in claim 17 , wherein: a time margin between a front end synchronizing signal detecting time of the forward direction scanning line and a starting time of the image section that is adjacent to the second non-image section, determined based on the first and the second light beams received by the light detecting unit, is a first time margin; a time margin between a front end synchronizing signal detecting time of the reverse direction scanning line and a starting time of the image section that is adjacent to the first non-image section, determined based on the first and the second light beams received by the light detecting unit, is a second time margin; and the first time margin and the second time margin are substantially equal.
22. The image forming apparatus as claimed in claim 21 , wherein the reflecting member and the light detecting unit are symmetrically provided in the first and the second non-image sections, respectively, with respect to a center of the image section.
23. The image forming apparatus as claimed in claim 17 , further comprising a control unit to determine whether the scanning line of the light beam is the forward direction or the reverse direction according to a difference between signals that respectively correspond to the first and the second light beams received by the light detecting unit, and to control the light source to emit a light beam that has the image information corresponding to a scanning direction of the scanning line.
24. The image forming apparatus as claimed in claim 17 , wherein the beam deflector comprises a resonance mirror.
25. The image forming apparatus as claimed in claim 17 , wherein the light scanning unit comprises only one light detecting unit.
26. A method of determining a scanning direction of a light beam, the method comprising: deflecting, by a beam deflector, the light beam to form forward direction and reverse direction scanning lines in an image section and first and second non-image sections respectively provided on opposite sides of the image section; reflecting, by a reflecting member, a light beam inputted from the beam deflector; receiving a first light beam directly inputted from the beam deflector, and a second light beam reflected by the reflecting unit; and determining whether the scanning line of the light beam is the forward direction or the reverse direction according to a difference between signals that respectively correspond to the received first and the received second light beams by the light detecting unit, wherein the reflecting member distinguishes the reflected second light beam from the first light beam.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
February 20, 2009
July 19, 2011
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